Windows are essential for light and views but, unfortunately, are also usually a building’s weakest link when it comes to security - and a regular glass window becomes a thousand razor-sharp projectiles when subjected to an explosion. Blast-resistant glass is designed to protect against this, but current blast-resistant glass is thick and expensive. Now researchers are developing and testing a new type of blast-resistant glass that will be thinner, lighter and less vulnerable to small-scale explosions.
Conventional blast-resistant window glass is generally a plastic layer sandwiched between two sheets of glass, and often more than an inch thick. But engineers at the University of Missouri (MU) are developing blast-resistant glass that replaces the plastic layer with a transparent composite material made of glass fibers embedded in plastic, resulting in glass that is less than one-half of an inch thick. Because the glass panel is thinner, it uses less material and will, therefore, be cheaper than what's currently in use.
The glass fibers embedded in the new glass add strength because, unlike plastic, they are only about 25 microns thick - about half the width of a typical human hair - and leave little room for defects in the glass that could lead to cracking. The use of a transparent composite interlayer also provides the flexibility to change the strength of the layer by changing the quantity of glass fiber within the glass and its orientation.
To observe how the glass reacts to small-scale explosions caused by a grenade or hand-delivered bomb, the researchers detonated a small explosive within close proximity of the window panel. After the blast, the glass panel was cracked but had no holes in the composite layer. Future tests will be done on larger pieces of glass that are equivalent to standard window size, and could potentially be followed by tests with large-scale explosions.
In addition to providing protection from small-scale explosions, the MU researchers say the super-strong glass could also protect residential windows from hurricane winds and debris or earthquakes.
Check out the video below to see the glass withstand a small scale explosion.